Epidural Steroids Ineffective for Sciatica

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This study reviewed randomized placebo-controlled trials to determine the efficacy of epidural corticosteroid injections for sciatica.

The pooled results showed a significant, though small, effect of epidural corticosteroid injections compared to placebo for leg pain in the short term.

Patients with sciatica derived minimal benefit from epidural corticosteroids, raising questions about the value of the treatment for the condition, authors of a meta-analysis concluded.

Pooled results of 23 clinical trials showed a small but statistically significant short-term improvement in leg pain with epidural injection of corticosteroids versus placebo, according to Rafael Zambelli Pinto, MSc, of the University of Sydney in Australia, and coauthors.

Long-term effects were even more modest and did not achieve statistical significance. Epidural corticosteroids had no effect on back pain, they reported online in Annals of Internal Medicine.

"The small effects were less than the proposed thresholds for clinically important change in pain and disability, which range from a reduction of 10 to 30 points on a 0 to 100 scale," the authors wrote of their findings.

"Until the current evidence changes we would recommend patients with acute sciatica receive a course of conservative care before any invasive treatment approach is considered," they added. "This conservative care should preferably follow evidence-based guidelines, such as those for neuropathic pain.

"For those patients who have persistent and disabling sciatica symptoms, epidural corticosteroids and surgery are the available treatment options, with short-term effects that need to be considered in the shared decision-making process."

Generally considered a condition with a self-limiting course, sciatica can persist and progress to disabling symptoms in some patients. Persistent, severe sciatica confers a four-fold increased risk of back surgery compared with patients who have persistent nonspecific low-back pain, the authors noted in their introduction.

Steroid treatment for back pain has been prominent in the news recently due to a fungal meningitis outbreak among back pain patients receiving tainted steroid injections from a Massachusetts compounding company.

Most clinical authorities recommend conservative treatment as the initial approach to sciatica, but patient series and case reports have suggested that pharmacologic and non-interventional therapies are ineffective or have only small effects.

Consequently, use of more invasive treatment, such as epidural corticosteroids, has become increasingly common as initial or early therapy, the authors continued.

Recent clinical guidelines and systematic reviews have reflected inconsistent views about the quality of evidence for epidural corticosteroid injection for sciatica.

"An important barrier to interpreting the results of many clinical trials investigating the use of epidural corticosteroid injections is that the comparator is often an active treatment of unknown effectiveness, rather than an inert placebo," the authors wrote.

"Another limitation is that even those guidelines recommending shared decision-making when considering the epidural corticosteroid injections as a short-term treatment options have failed to consider the size of the treatment effects, expressed in terms of patient-relevant outcomes."

Moreover, previous studies and reviews failed to take into account the efficacy of all three approaches to epidural injections: caudal, interlaminar, and transforaminal.

To address the limitations of available evidence, Pinto and colleagues performed a systematic review of reported studies of epidural corticosteroid injections for persistent sciatica. They limited the search to placebo-controlled trials that permitted use of any of the three approaches to epidural injection.

Eligibility criteria did not stipulate a symptom duration, but study participants' symptomatology was classified as acute (<6 weeks), subacute (6 to 12 weeks), chronic (≥12 weeks), or mixed. Pinto and colleagues excluded trials that included patients who had undergone surgery for sciatica or who had sciatic symptoms associated with spinal canal stenosis.

Investigators converted reported scores for pain intensity and disability to a scale of 0 (no pain or disability) to 100 (worst possible pain or disability). They calculated results for short-term (2 weeks to 3 months) and long-term (≥12 months) follow-up.

The final analyses comprised 25 publications and 23 clinical trials. The meta-analysis of short-term outcomes included 14 trials and 1,316 patients. Pooled data showed a mean decrease in leg-pain scores of 6.2 for epidural corticosteroids versus placebo. Analysis of pooled data from six trials showed no difference between treatment groups for back pain.

Short-term disability improved modestly but significantly, as reflected in a mean difference of 3.1 in favor of epidural corticosteroids in an analysis of 10 trials that included 1,154 patients.

Analyses of long-term outcomes showed no significant differences between treatment groups for leg pain, back pain, or disability.

Studies included in the analyses of short- and long-term follow-up met criteria for high-quality evidence.

"The small size of the treatment effects raises questions about the clinical utility of this procedure in the target population," Pinto and co-authors wrote in conclusion.

The authors had no relevant disclosures.

Reviewed by Zalman S. Agus, MD Emeritus Professor, Perelman School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA, BSN, RN, Nurse Planner

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